Objects difference between . and [] Record Collection

JavaScript
1

Hi evrybody!

First of all sorry for my English.

I’m struggling against a great confusion at a JS challenge and its sintaxis. This one specifically:

I wrote this and it didn’t work (obv).

 function updateRecords(object, id, prop, value) {
  if (prop != "tracks" && value != ""){
       object.id.prop = value;
   } else if (prop == "tracks" && !object.id.hasOwnProperty("tracks")){
     object.id.prop = [value];
   } else if ( prop == "tracks" && value != ""){
     object.id.prop.push(value);
   } else if (value == ""){
     delete object.id.prop;
   }
 
   return object;
 }

After a while i decided to take a look at the hints and I saw that the conditions and if statements were OK and the only difference was that I used dots to access to the objects instead of brackets.

I followed what the previous challenges taught me and I realy didn’t find any difference between trying to access to an object properties using . or …

So that’s why I open this topic. I have no problems with the logic of the challenge. My problem is that I cant understand why the function works only with brackets and not with dots as I did in previous challenges.

Thanks you all!

This is the solution:

 function updateRecords(object, id, prop, value) {
   if (prop !== 'tracks' && value !== "") {
     object[id][prop] = value;
   } else if (prop === "tracks" && !object[id].hasOwnProperty("tracks")) {
     object[id][prop] = [value];
   } else if (prop === "tracks" && value !== "") {
     object[id][prop].push(value);
   } else if (value === "") {
     delete object[id][prop];
   }
   return object;
 }
2

Hi @balbert94!

Welcome to the forum!

I have added the [spoiler] tags to your code for those users who haven’t worked on this challenge yet.

1 Like
3

the relevant challenge is this one, review it and let us know if you have still doubts

1 Like
4

omg looks like I’ll have to look for online english courses too hahaha :rofl:

so variables go always inside brackets right? I really didn’t realize that difference.

Thank you very much for answering so quickly.

Should I delete the post? Looks like a pointless question now…

5

omg looks like I’ll have to look for online english courses too hahaha

Theres soooooo much to keep track of and soooooo many interlocking pieces - don’t be too hard on yourself.

so variables go always inside brackets right?

Yes, if the property name is in stored a variable. The other use case is if the property name is not a valid JS identifier, like starting with a number, has a space in it, etc.

Should I delete the post? Looks like a pointless question now…

No, someone else could benefit.

6

Also, you wouldn’t be able to delete the post if you wanted to because only moderators can delete posts with replies attached to them.